Ann Rule, the former co-worker and friend of serial killer Ted Bundy who went on to become a prolific true crime writer, has died. Several of her books were turned into TV movies, and she was a frequent guest on true crime TV shows, including 48 Hours. She died on Sunday after suffering a heart attack. She was 83.

Rule was a budding author in the early 1970s, living in Seattle and working on a book about a local serial killer. She didn’t know it then, but one of her co-workers at the local suicide hotline was the psychotic murderer the police were looking for: Bundy. After his arrest, she was convinced he was innocent, an opinion that changed after he escaped from jail and went on another killing spree in Florida.

The book she wrote, told from her unique prospective of being a friend of the killer, was called The Stranger Beside Me, which was turned into the 2003 TV movie Ann Rule Presents: The Stranger Beside Me, starring Billy Campbell as Bundy, with Barbara Hershey playing Rule. Her Rule other books turned into TV movies include Hunt For The I-5 Killer, Too Late To Say Goodbye, Every Breath You Take, Small Sacrifices and Never Let Her Go.

Shortly before her death, Rule was allegedly the victim of crime herself – at the hands of her own sons, Michael and Andrew Rule, who authorities say stole more than $100,000 from her and then demanded more while she “cowered in her wheelchair.”